C. both A and B

D. all of these

Most marine animals live near the surface of the ocean because of _____, which supports photosynthesis by marine algae that form the basis of the food chain.
A. sunlight
B. warmer temperatures
C. air
D. all of these

B. intertidal zone

A. primary productivity

The amount of carbon fixed by organisms through the synthesis of organic matter using energy derived from solar radiation is called _____.
A. primary productivity
B. photosynthesis
C. chemosynthesis
D. none of these

SKIP

A. outgassing of elements from Earth's interior

The dissolved materials in seawater are thought to originate from chemical weathering of rocks on the continents and also from _____.
A. outgassing of elements from Earth's interior
B. organisms
C. evaporation of fresh water
D. erosion
E. none of these

B. cold, nutrient-rich water from the ocean depths to the surface

An ocean upwelling carries
A. warm water from the central ocean toward the coasts.
B. cold, nutrient-rich water from the ocean depths to the surface
C. warm water from the ocean depths to the surface
D. nutrients down to the deep ocean